Combined evaluation of bubble dynamics, polydispersion model and turbulence modeling for adiabatic two-phase flow

Abstract

The paper deals with the modeling and the numerical simulation of upward bubbly flow in a new experimental test, named CHAPTAL. The CHAPTAL experimental program has been set up in the framework of the NEPTUNE project. Its aim is to locally characterize the hydraulics (phase topology and dynamic quantities) of an adiabatic high pressure bubbly flow in a vertical tube.The CHAPTAL test section is a 5m long vertical pipe with an inside diameter of 38mm. The CHAPTAL test deals with pressure up to 10bars. The working liquid fluid is water. Gas bubbles are made of R116 refrigerant fluid. The resulting flow is an adiabatic two-phase flow.R116 wall injection creates bubbles of 2–4mm outer diameter. The local measurements characterize each phase at three elevations with bi-hot-film and bi-optical probes.Concerning the liquid phase, mean axial velocity, mean radial velocity, axial turbulent intensity and radial turbulent intensity are measured by the bi-hot-film probes. Concerning the gaseous phase, void fraction, interface velocity, interfacial area concentration and Sauter mean diameter are measured by bi-optical probes.The paper aims at providing new measurements of an upward bubbly flow, for which non-dimensional numbers are representative of pressurized water reactor (PWR) conditions. Interfacial momentum transfer, polydispersion and turbulence modeling are evaluated in this context.